The Astrophysical Journal Letters最新文献

{"title":"Discovery of the Seven-ring Polycyclic Aromatic Hydrocarbon Cyanocoronene (C24H11CN) in GOTHAM Observations of TMC-1","authors":"Gabi Wenzel, Siyuan Gong, Ci Xue, P. Bryan Changala, Martin S. Holdren, Thomas H. Speak, D. Archie Stewart, Zachary T. P. Fried, Reace H. J. Willis, Edwin A. Bergin, Andrew M. Burkhardt, Alex N. Byrne, Steven B. Charnley, Andrew Lipnicky, Ryan A. Loomis, Christopher N. Shingledecker, Ilsa R. Cooke, Michael C. McCarthy, Anthony J. Remijan, Alison E. Wendlandt and Brett A. McGuire","doi":"10.3847/2041-8213/adc911","DOIUrl":"https://doi.org/10.3847/2041-8213/adc911","url":null,"abstract":"We present the synthesis and laboratory rotational spectroscopy of the seven-ring polycyclic aromatic hydrocarbon (PAH) cyanocoronene (C24H11CN) using a laser-ablation-assisted cavity-enhanced Fourier transform microwave spectrometer. A total of 71 transitions were measured and assigned between 6.8 and 10.6 GHz. Using these assignments, we searched for emission from cyanocoronene in the Green Bank Telescope (GBT) Observations of TMC-1: Hunting Aromatic Molecules project observations of the cold dark molecular cloud TMC-1 using the 100 m GBT. We detect a number of individually resolved transitions in ultrasensitive X-band observations and perform a Markov Chain Monte Carlo analysis to derive best-fit parameters, including a total column density of at a temperature of K. A spectral stacking and matched filtering analysis provides a robust 17.3σ significance to the overall detection. The derived column density is comparable to that of cyano-substituted naphthalene, acenaphthylene, and pyrene, defying the trend of decreasing abundance with increasing molecular size and complexity found for carbon chains. We discuss the implications of the detection for our understanding of interstellar PAH chemistry and highlight major open questions and next steps.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of Methane in the Closest Extreme Metal-poor T Dwarf WISEA J181006.18−101000.5*","authors":"Jerry J.-Y. Zhang, 俊䶮 章, Nicolas Lodieu, Eduardo L. Martín, Pascal Tremblin, María Rosa Zapatero Osorio, Víctor J. S. Béjar, Nikola Vitas, Bartosz Gauza, Yakiv V. Pavlenko and Rafael Rebolo","doi":"10.3847/2041-8213/adc91f","DOIUrl":"https://doi.org/10.3847/2041-8213/adc91f","url":null,"abstract":"WISEA J181006.18−101000.5 (WISE1810) is the nearest metal-poor ultracool dwarf to the Sun. It has a low effective temperature and has been classified as an extreme early-T subdwarf. However, methane, the characteristic molecule of the spectral class T, was not seen in the previous low-resolution spectrum. Using the 10.4 m Gran Telescopio Canarias, we collected a high-quality JHK-band intermediate-resolution R ≈ 5000 spectrum of WISE1810, in which 17 ± 6 ppm of methane is clearly detected, while carbon monoxide is absent. Based on a custom computed ATMO2020++ model, we estimated an effective temperature of 1000 ± 100 K, a high surface gravity of dex, and a carbon abundance of [C/H] = −1.5 ± 0.2 dex, inferring [Fe/H] = −1.7 ± 0.2 dex. Potassium is not seen in our data, and the upper limits of the pseudoequivalent width of the J-band atomic lines are at least 25–60 times weaker than those measured from solar-metallicity early-T counterparts. We measured a heliocentric radial velocity of −83 ± 13 km s−1, inferring that WISE1810 is more likely a thick-disk member.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal Behavior and Latitudinal Relationships between Key Solar Parameters and Green Line Emissions in the Solar Corona","authors":"Jacob Oloketuyi, Yu Liu, Linhua Deng, Abouazza Elmhamdi, Khaled Nasser Almosabeh, Fengrong Zhu, Haitang Li, Feiyang Sha, Qiang Liu, Oladipo Emmanuel Abe, Charles Owolabi and Olufemi Olusola","doi":"10.3847/2041-8213/adcb38","DOIUrl":"https://doi.org/10.3847/2041-8213/adcb38","url":null,"abstract":"Understanding the link between solar parameters and their influence on green line emissions would help unravel the complexities of eruptive phenomena within the solar corona. This study explores the intricate relationship between green line emissions and various solar indicators, including flares, F10.7 cm flux, and sunspot numbers. Utilizing data from both ground-based and space-based sources spanning from 1996 to 2024, covering solar cycles 23 to 25, the investigation employs the multitaper and cross-correlation analyses. The study reveals distinct behaviors and contributions to green line emissions at low and high latitudes. The F10.7 cm radio flux exhibits zero lag with green line emissions, indicating that both are contemporaneously influenced by solar activity, as shown by their correlation with sunspot numbers. In contrast, B-, M-, and X-class flares typically act as precursors or aftermaths of such activity. C-class flares exhibit a pronounced positive correlation with the green line, causally linked to plasma dynamics, particularly at low latitudes. Sunspots, on the other hand, act as a leading and significant indicator of the green line with positive lag, preceding the emissions. The emissions are found to be an excellent indicator of solar activity, with an immediate response to the F10.7 cm flux and a delayed response to sunspot emergence. The differences in observed impacts could be attributed to the behavior of confined plasma within magnetic loops, influenced by factors such as solar magnetic configurations, differential rotation, and dynamo mechanisms. These factors collectively impact the global coronal structure and influence the green line across latitudes.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Evidence for r-process Nucleosynthesis in Delayed MeV Emission from the SGR 1806–20 Magnetar Giant Flare","authors":"Anirudh Patel, Brian D. Metzger, Jakub Cehula, Eric Burns, Jared A. Goldberg and Todd A. Thompson","doi":"10.3847/2041-8213/adc9b0","DOIUrl":"https://doi.org/10.3847/2041-8213/adc9b0","url":null,"abstract":"The origin of heavy elements synthesized through the rapid neutron capture process (r-process) has been an enduring mystery for over half a century. J. Cehula et al. recently showed that magnetar giant flares, among the brightest transients ever observed, can shock heat and eject neutron star crustal material at high velocity, achieving the requisite conditions for an r-process. A. Patel et al. confirmed an r-process in these ejecta using detailed nucleosynthesis calculations. Radioactive decay of the freshly synthesized nuclei releases a forest of gamma-ray lines, Doppler broadened by the high ejecta velocities v ≳ 0.1c into a quasi-continuous spectrum peaking around 1 MeV. Here, we show that the predicted emission properties (light curve, fluence, and spectrum) match a previously unexplained hard gamma-ray signal seen in the aftermath of the famous 2004 December giant flare from the magnetar SGR 1806–20. This MeV emission component, rising to peak around 10 minutes after the initial spike before decaying away over the next few hours, is direct observational evidence for the synthesis of ∼10−6 M⊙ of r-process elements. The discovery of magnetar giant flares as confirmed r-process sites, contributing at least ∼1%–10% of the total Galactic abundances, has implications for the Galactic chemical evolution, especially at the earliest epochs probed by low-metallicity stars. It also implicates magnetars as potentially dominant sources of heavy cosmic rays. Characterization of the r-process emission from giant flares by resolving decay line features offers a compelling science case for NASA’s forthcoming COSI nuclear spectrometer, as well as next-generation MeV telescope missions.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"exoALMA. VIII. Probabilistic Moment Maps and Data Products Using Nonparametric Linear Models","authors":"Thomas Hilder, Andrew R. Casey, Daniel J. Price, Christophe Pinte, Andrés F. Izquierdo, Caitlyn Hardiman, Jaehan Bae, Marcelo Barraza-Alfaro, Myriam Benisty, Gianni Cataldi, Pietro Curone, Ian Czekala, Stefano Facchini, Daniele Fasano, Mario Flock, Misato Fukagawa, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Iain Hammond, Jane Huang, John D. Ilee, Kazuhiro Kanagawa, Geoffroy Lesur, Cristiano Longarini, Ryan Loomis, Ryuta Orihara, Giovanni Rosotti, Jochen Stadler, Richard Teague, Hsi-Wei Yen, Gaylor Wafflard, Andrew J. Winter, Lisa Wölfer, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc435","DOIUrl":"https://doi.org/10.3847/2041-8213/adc435","url":null,"abstract":"Extracting robust inferences on physical quantities from disk kinematics measured from Doppler-shifted molecular line emission is challenging due to the data’s size and complexity. In this paper, we develop a flexible linear model of the intensity distribution in each frequency channel, accounting for spatial correlations from the point-spread function. The analytic form of the model’s posterior enables probabilistic data products through sampling. Our method debiases peak intensity, peak velocity, and line width maps, particularly in disk substructures that are only partially resolved. These are needed in order to measure disk mass, turbulence, and pressure gradients and detect embedded planets. We analyze HD 135344B, MWC 758, and CQ Tau, finding velocity substructures 50–200 m s−1 greater than with conventional methods. Additionally, we combine our approach with discminer in a case study of J1842. We find that uncertainties in stellar mass and inclination increase by an order of magnitude due to the more realistic noise model. More broadly, our method can be applied to any problem requiring a probabilistic model of an intensity distribution conditioned on a point-spread function.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"exoALMA. II. Data Calibration and Imaging Pipeline","authors":"Ryan A. Loomis, Stefano Facchini, Myriam Benisty, Pietro Curone, John D. Ilee, Gianni Cataldi, Hsi-Wei Yen, Richard Teague, Christophe Pinte, Jane Huang, Himanshi Garg, Ryuta Orihara, Ian Czekala, Brianna Zawadzki, Sean M. Andrews, David J. Wilner, Jaehan Bae, Marcelo Barraza-Alfaro, Daniele Fasano, Mario Flock, Misato Fukagawa, Maria Galloway-Sprietsma, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Cristiano Longarini, Francois Menard, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, Gaylor Wafflard-Fernandez, Lisa Wölfer and Tomohiro C. Yoshida","doi":"10.3847/2041-8213/adc43a","DOIUrl":"https://doi.org/10.3847/2041-8213/adc43a","url":null,"abstract":"The exoALMA Large Program was designed to search for subtle kinematic deviations from Keplerian motion, indicative of embedded planets, in high-angular-resolution and high-spectral-resolution Band 7 observations of 12CO, 13CO, and CS emission from protoplanetary disks. This Letter summarizes the calibration and imaging pipelines used by the exoALMA collaboration. With sources ranging in diameter from to when probed by 12CO, multiple antennae configurations were required to maximally recover all spatial information (including Atacama Compact Array data for seven sources). Combining these data sets warranted particular care in their alignment during calibration and prior to imaging so as not to introduce spurious features that might resemble the kinematic deviations being investigated. Phase decoherence was found in several data sets, which was corrected by an iterative self-calibration procedure, and we explored the effects of the order of operations of spatial alignment, flux scaling, and self-calibration. A number of different imaging sets were produced for the continuum and line emission, employing an iterative masking procedure that minimizes bias due to non-Keplerian motions in the disk.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"exoALMA. XIV. Gas Surface Densities in the RX J1604.3−2130 A Disk from Pressure-broadened CO Line Wings","authors":"Tomohiro C. Yoshida, Pietro Curone, Jochen Stadler, Stefano Facchini, Richard Teague, Munetake Momose, Sean M. Andrews, Jaehan Bae, Marcelo Barraza-Alfaro, Myriam Benisty, Gianni Cataldi, Daniele Fasano, Mario Flock, Misato Fukagawa, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Cristiano Longarini, Ryan A. Loomis, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Giovanni Rosotti, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Lisa Wölfer and Brianna Zawadzki","doi":"10.3847/2041-8213/adc42f","DOIUrl":"https://doi.org/10.3847/2041-8213/adc42f","url":null,"abstract":"Gas surface density is one of the most relevant physical quantities in protoplanetary disks. However, its precise measurement remains highly challenging due to the lack of a direct tracer. In this study, we report the spatially resolved detection of pressure-broadened line wings in the CO J = 3–2 line in the RX J1604.3−2130 A transition disk as part of the exoALMA large program. Since pressure-broadened line wings are sensitive to the total gas volume density, we robustly constrain the radial dependence of the gas surface density and midplane pressure in the region located 50–110 au from the central star, which encompasses the dust ring of the system. The peak radius of the midplane pressure profile matches the dust ring radial location, directly proving radial dust trapping at a gas pressure maximum. The peak gas surface density is 18–44 g cm−2 and decreases at radii interior to and exterior of the dust ring. A comparison of the gas and dust surface densities suggests that the disk turbulence is as low as αturb ∼ 2 × 10−4. Despite dust trapping, the gas-to-dust surface density ratio at the ring peak is 70–400, which implies already-formed protoplanets and/or less efficient dust trapping. The gas surface density drop at radii interior to the ring is consistent with a gas gap induced by a Jupiter-mass planet. The total gas mass within 50 < r < 110 au is estimated to be ∼0.05–0.1 M⊙(50–100 MJup), suggesting that planetary system formation is possible.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"exoALMA. VII. Benchmarking Hydrodynamics and Radiative Transfer Codes","authors":"Jaehan Bae, Mario Flock, Andrés Izquierdo, Kazuhiro Kanagawa, Tomohiro Ono, Christophe Pinte, Daniel J. Price, Giovanni P. Rosotti, Gaylor Wafflard-Fernandez, Geoffroy Lesur, ‪Frédéric Masset, Sean M. Andrews, Marcelo Barraza-Alfaro, Myriam Benisty, Gianni Cataldi, Nicolás Cuello, Pietro Curone, Ian Czekala, Stefano Facchini, Daniele Fasano, Maria Galloway-Sprietsma, Cassandra Hall, Iain Hammond, Jane Huang, Giuseppe Lodato, Cristiano Longarini, Jochen Stadler, Richard Teague, David J. Wilner, Andrew J. Winter, Lisa Wölfer and Tomohiro C. Yoshida","doi":"10.3847/2041-8213/adc436","DOIUrl":"https://doi.org/10.3847/2041-8213/adc436","url":null,"abstract":"Forward modeling is often used to interpret substructures observed in protoplanetary disks. To ensure the robustness and consistency of the current forward-modeling approach from the community, we conducted a systematic comparison of various hydrodynamics and radiative transfer codes. Using four grid-based hydrodynamics codes (FARGO3D, Idefix, Athena++, and PLUTO) and a smoothed-particle hydrodynamics code (Phantom), we simulated a protoplanetary disk with an embedded giant planet. We then used two radiative transfer codes (mcfost and RADMC-3D) to calculate disk temperatures and create synthetic 12CO cubes. Finally, we retrieved the location of the planet from the synthetic cubes using DISCMINER. We found strong consistency between the hydrodynamics codes, particularly in the density and velocity perturbations associated with planet-driven spirals. We also found a good agreement between the two radiative transfer codes: the disk temperature in mcfost and RADMC-3D models agrees within ≲3% everywhere in the domain. In synthetic 12CO channel maps, this results in brightness temperature differences within ±1.5 K in all our models. This good agreement ensures consistent retrieval of planet’s radial/azimuthal location with only a few percent of scatter, with velocity perturbations varying ≲20% among the models. Notably, while the planet-opened gap is shallower in the Phantom simulation, we found that this does not impact the planet location retrieval. In summary, our results demonstrate that any combination of the tested hydrodynamics and radiative transfer codes can be used to reliably model and interpret planet-driven kinematic perturbations.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"271 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"exoALMA. XIII. Gas Masses from N2H+ and C18O: A Comparison of Measurement Techniques for Protoplanetary Gas Disk Masses","authors":"Leon Trapman, Cristiano Longarini, Giovanni P. Rosotti, Sean M. Andrews, Jaehan Bae, Marcelo Barraza-Alfaro, Myriam Benisty, Gianni Cataldi, Pietro Curone, Ian Czekala, Stefano Facchini, Daniele Fasano, Mario Flock, Misato Fukagawa, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Andres F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Ryan A. Loomis, Ryuta Orihara, Teresa Paneque-Carreno, Christophe Pinte, Daniel Price, Jochen Stadler, Richard Teague, Sierk van Terwisga, Leonardo Testi, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Lisa Wölfer, Tomohiro C. Yoshida, Brianna Zawadzki and Ke Zhang","doi":"10.3847/2041-8213/adc430","DOIUrl":"https://doi.org/10.3847/2041-8213/adc430","url":null,"abstract":"The gas masses of protoplanetary disks are important but elusive quantities. In this work we present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of N2H+ (3–2) for 11 exoALMA disks. N2H+ is a molecule sensitive to CO freeze-out and has recently been shown to significantly improve the accuracy of gas masses estimated from CO line emission. We combine these new observations with archival N2H+ and CO isotopologue observations to measure gas masses for 19 disks, predominantly from the exoALMA large program. For 15 of these disks the gas mass has also been measured using gas rotation curves. We show that the CO + N2H+ line emission-based gas masses typically agree with the kinematically measured ones within a factor of 3 (∼1σ–2σ). Gas disk masses from CO + N2H+ are on average a factor of lower than the kinematic disk masses, which could suggest slightly lower N2 abundances and/or lower midplane ionization rates than typically assumed. Herbig disks are found to have CO gas abundances at the level of the interstellar medium based on their CO and N2H+ fluxes, which sets them apart from T Tauri disks, where abundances are typically ∼3−30× lower. The agreement between CO + N2H+-based and kinematically measured gas masses is promising and shows that multimolecule line fluxes are a robust tool to accurately measure disk masses at least for extended disks.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Estimates of the Spin and Accretion Rate of the Black Hole M87*","authors":"Michael Drew, Joshua S. Stanway, Brett A. Patterson, Timothy J. Walton and Derek Ward-Thompson","doi":"10.3847/2041-8213/adc90e","DOIUrl":"https://doi.org/10.3847/2041-8213/adc90e","url":null,"abstract":"In this Letter, we use the imaging results of M87* from the Event Horizon Telescope (EHT) to calculate the rotational velocity of the inner edge of the accretion disk and find a value of ∼0.14c. We then calculate the dimensionless spin parameter, a, of the black hole, obtaining a value of a ∼ 0.8. We deduce that this is probably a lower limit. We go on to use the results of the EHT polarization study of the magnetic field direction in the accretion disk of M87* as a proxy for the direction of motion of the spiralling accreting matter in this highly ionized disk. This direction is defined by the vector sum of the tangential rotation velocity and the inward radial accretion velocity. We thus calculate the accretion velocity to be ∼(7 ± 0.7) × 107 ms−1. We go on to estimate a range of values for the accretion rate from the inner disk to be ∼4 × 10−5 to ∼4 × 10−1M⊙ yr−1, and a range of values for the accretion power to be ∼1034–1038 J s−1. This is the same range as the power of the jet, making it consistent with accretion-driven jet models.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}